Composite movable partition for pressure vessel



J. H. MERCIER Jan. 25, 1966 COMPOSITE MOVABLE PARTITION FOR PRESSUREVESSEL 2 Sheets-Sheet 1 Original Filed Dec. 9, 1959 R P A N Q Y Jan. 25,1966 J. H. MERCIER COMPOSITE MOVABLE PARTITION FOR PRESSURE VESSELOriginal Filed Dec. 9, 1959 2 Sheets-Sheet z 8 I5 79 768 5 74 L70 M 76I! :92 97 a/ 73 92 $2 94 F/G. 6 99 INVENTOR. Jwcaz/islifl'lec/fl? BY *5?DEAN. FA L v #uescd United States Patent 3,230,975 COMPOSITE MOVABLEPARTITION FOR PRESSURE VESSEL Jacques H. Mercier, New York, N.Y.,assignor to Mercier Olaer Patent Corporation, Wilmington, Del., acorporation of Delaware Original application Dec. 9, 1959, Ser. No.858,349. Divided and this application Apr. 12, 1963, Ser. No.

1 Claim. (Cl. 13s s0 This application is a division of co-pendingapplication Serial No. 858,349, filed December 9, 1959, now abandoned.

This invention relates to the art of pressure vessels and moreparticularly to pressure vessels in which two fluids are separated by amovable partition.

As conducive to an understanding of the invention, according to oneaspect thereof, it is noted that in a pressure vessel, such as apressure accumulator of the type having a rigid shell with a bladdertherein intervening between the gas and oil ports thereof, in order toprovide for substantially complete expulsion of the oil from thecontainer the bladder must be capable of stretching progressively toengage the wall of the container as shown, for example, in ReissuePatent No. 23,437, to prevent formation of oil pockets, with resultantentrapment of oil.

To permit such progressive expansion of the bladder it is generally madeof an elastomer, such as synthetic rubber, which, however, issubstantially permeable to gas and, consequently, if the accumulatorshould stand for any considerable period with a gas and oil pre-charge,the gas would seep into the oil, with resultant pressure drop, whichcould have serious consequences such as when the accumulator operates acircuit breaker and the presence of gas in the oil would cause improperfunctioning of uch circuit breaker.

It is accordingly among the objects of the invention to provide apressure vessel of relatively low cost which will function withoutlikelihood of mixture of the two fluids therein even after thepro-charged unit has been standing for along period of time.

According to the invention, these objects are accomplished by thearrangement and combination of elements hereinafter described and moreparticularly recited in the claim.

In the accompanying drawings in which are shown one or more of variouspossible embodiments of the several features of the invention,

FIG. 1 is a longitudinal sectional view of a pressure vessel accordingto the invention, with the bladder thereof in distended butsubstantially unstretched condition,

FIG. 2 is a view similar to FIG. 1, with the bladder in partiallycollapsed condition,

FIG. 3 is a view similar to FIG. 1, with the bladder in fully extendedcondition filling the container,

FIG. 4 is a fragmentary view showing another embodiment of the bladder,

FIG. 5 is a fragmentary view showing another embodiment of the bladderretaining means, and

FIG. 6 is a longitudinal sectional view of another embodiment of theinvention.

Referring now to the drawings, the pressure vessel shown illustrativelyis a pressure accumulator which desirably comprises a container 11,preferably of strong rigid material such as steel, cast aluminum or thelike, capable of withstanding high pressure and having a gas inlet port12 and a liquid port 13 therein preferably opposed to each other.

The container 11 may be spherical or cylindrospherical, as shown, andhas a collapsible and expandable bladder 14 therein of resilientmaterial such as rubber or synthetic plastic of like physicalcharacteristics, which in distended but substantially unstretchedcondition, as shown in FIG. 1, is smaller than the cavity of container11 and has its longitudinal axis aligned with ports 12 and 13, thebladder defining a gas and oil chamber on opposed sides thereof.

In the illustrative example herein shown, the bladder is an elastomersuch as synthetic rubber, which may be buna-N, bntyl or the like, whichcan fold between its natural shape shown in FIG. 1 and its partiallycollapsed shape shown in FIG. 2, and which can expand to conform to thecontour of the container as shown in FIG. 3. A bladder formed from suchmaterial is, however, substantially permeable to gas but is required forthe reasons hereinafter set forth.

As shown in FIG. 1, the bladder has a port or mouth at one end, having athickened rim 15, and is of greatest diameter adjacent said mouth, as at16, the portion 17 of the bladder from said greatest diameter portion 16to the free end 18 thereof being substantially conical in contour.

The bladder 14 is rigidly affixed in the container 11, preferably bymeans of a fitting 21, which desirably has a substantially cylindricalstem portion 22, with a base disc presenting an outstanding lateralflange 23 at one end thereof which desirably has an annular groove 24 inits upper face 25 in which may be positioned the thickened rim 15 aboutthe mouth of the bladder 14.

Positioned in the bladder 14 is a secondary bladder 27 of thindeformable material whose natural shape is such as to substantiallycompletely fill the interior of the container as shown in FIG. 3. Thebladder 27 illustratively is of material which is substantiallynon-permeable and non-resilient. Typical of such materials are Du Poutpolyurethane, sold under the trade name of Mylar, and polyvinylchloride, sold under the trade name of PVC.

The mouth 28 of bladder 27 also is positioned in the annular groove 24of fitting 21 and when the parts are assembled as shown in FIG. 1 thebladders 14 and 27 may be securely clamped in place by means of a nut 29screwed upon the protruding threaded stem of the fitting, an annularshoulder 31 adjacent the root end of the stem abutting against the rimof the gas inlet port 12 to prevent cutting of the rim 15 of the bladder14 and the mouth 28 of bladder 27 by excessive tightening of the nut.

Although the outlet port 13 of the accumulator could be controlled inany suitable manner, in the embodiment herein shown it is preferred touse the general construction shown in Patent No. 2,469,171, dated May 3,1949, by the use of which an outlet closure assembly 41 aflixed in saidport 13 may be removed without likelihood of injury to the mechanic. Asshown in FIG. 1, this assembly desirably comprises a housing 42,preferably a tubular member which desirably has an external annularshoulder 43 at the upper end thereof of outer diameter less than that ofport 13. A locking member 44, illustratively a ring of greater outerdiameter than said port 13 and deformable to permit its insertionthereinto, encompasses said tubular member and is seated on the rim 45of the port 13, the inner diameter of said ring 44 being less than theouter diameter of shoulder 43 so that said shoulder may seat on saidring. Encompassing said tubular memher and in juxtaposition with saidport 13 is a rubber gasket 46 which serves effectively to preventleakage between the wall of port 13 and the outer wall of tubular member42 when a nut 47 is screwed on the external threaded portion of saidtubular member 42.

Desirably positioned in said tubular member 42 is a poppet valvecomprising a valve head 51 adapted to seat on the bevelled mouth 52 oftubular member 42 and having a stem 53 preferably formed integraltherewith. Stem 53 is slidably mounted in bearing opening 54 desirablyin a disc 55 mounted in the bore of tubular member 42 said disc having aplurality of openings 56 therethrough to permit the passage of fluid,said valve head being normally retained in open position by means of acoil spring 57 encompassing stem 53 between head 51 and disc 55. As theconstruction and operation of said outlet closure assembly per se formsno part of this invention, it will not be'further described.

With the construction of the stretchable bladder 14 and the container 11above described, the distance of the partly inflated bladder 14, asshown in FIG. 1, from the inner surface of the container 11 increasesprogressively from near the largest diameter portion 16 of the bladdertoward the free end 18 thereof, and the size, shape and elasticcharacteristics of the bladder are selected so that in the furtherexpansion of the bladder from its expanded but unstretched conditionshown it will progressively engage such inner surface of the container11 from the portion 16 of the bladder toward its free end.

Although the secondary bladder 27 is substantially nonresilient, sinceits normal shape is such that it would substantially fill the containeras shown in FIG. 3, it is apparent that when the bladder 14 iscompressed, as shown in FIG. 2, the secondary bladder 27 will becrumpled into' a large number of folds and as the bladder 14 expands andstretches, the secondary bladder 27 will also expand to its fullydistended shape shown in FIG. 3.

In normal operation of the unit, it is first precharged by forcing gasunder pressure through the fitting 22 to fill the secondary bladder 27,causing the latter as well as the stretchable bladder 14 to expand tosubstantially the shape of the container. Thereupon, the fitting 22 issealed and a fluid such as oil under pressure considerably greater thanthat pre-charged into the bladder 27 is forced through the tubularmember 42 to compress the charged bladders so that they assume theposition shown in FIG. 2, for example, and a valve (not shown)controlling the oil port 13 is then closed.

To use the charged unit, the valve controlling the liquid outlet port 13is opened and the bladders 14 and 27 will expand to force liquid fromport 13. Since the bladder 14 will progressively engage the containerwall from the maximum diameter portion 16 thereof to the other end 18thereof, no liquid pockets will be formed between the bladder and therigid wall of the container.

As a result, substantially all of the fluid in the container 11 will beforced toward the outlet port 13 for expulsion therefrom. When thebladder has expanded sufficiently to engage the valve head 51, thelatter will be moved onto its seat, thereby closing the oil portion toprevent extrusion of the bladder, this occurring when the bladder 14 hasexpanded to engage substantially the entire wall surface of thecontainer and expelled substantially all of the oil from the container.

As the bladder 27 is substantially non-permeable, the pre-charged unitcan remain standing for long periods of time without likelihood that anygas will escape into the oil with resultant loss of gas pressure whenthe unit is ultimately used, and also without likelihood of mixture ofthe gas and oil, which might be serious where the two are notcompatible.

Where it is desired to provide communication from the space S betweenthe two bladders 14 and 27, either for venting such space or forcharging the latter with an additional fluid, the construction shown inFIG. is preferred.

Thus, a fitting 21 is provided that has a substantially cylindrical stemportion 22 with a base disc presenting an outstanding lateral flange 23at one end thereof, which desirably has an annular groove 24 in itsupper surface 25 and an annular shoulder 65 adjacent the root end ofstem 22 and in a plane above that of surface 25, the groove 24 carryingthe thickened rim 66 about the mouth of bladder 27.

Associated with the stem 22 is a disc 67 having a central bore 68through which the stem 22. extends. The portion of disc 67 around thelower periphery of said bore is seated on shoulder and an annular groove69 is provided in the underface of disc 67 also to receive the rim 66 ofbladder 27.

The disc 67 has an inwardly extending annular rim 71 at the lower end ofthe bore 68 which serves to space the remaining portion of said borefrom the stem 22, and the upper surface of disc 67 has an annular groove72 to receive the thickened rim 15 about the mouth of bladder 14.

Communication is offered from the space S between: the bladders 14 and27 to the exterior of the pressure: vessel by means of a radialpassageway 74 through said. disc 67 which leads into the bore 68thereof, said stem 22'- having a longitudinal passageway 75 and acommunicating lateral passageway 76 that leads into said bore 68.

Desirably, a plug 77 is provided at the outer end of passageway 75 toseal the latter.

The stem 22 is also encompassed by a rigid clamp plate 78 which extendsover the thickened rim 15 of bladder 14 and a resilient disc 79 alsoencompasses the stem 22 between plate 78 and the container wall.

Thus, when a nut 29 encompassing the protruding portion of stem 22 istightened, the mouths ofbladders 14 and 27 will be securely retained inposition, an annular shoulder 70 on said stem abutting against the rimof the gas inlet port 12 to prevent cutting of said disc 78 by excessivetightening of nut 29.

With this construction, the gas in the space S between bladders 14 and27 may readily be evacuated, and if desired, an intermediary fluid maybe introduced in such space. Thus, for example, where there is aradioactive fluid in contact with resilient bladder 14 and anon-radioactive fluid in contact with the non-permeable bladder 27, aprotective fluid could be introduced into space S to preventcontamination of such non-radioactive fluid.

With the constructions shown in FIGS. 1 to 5, the stretchable andpermeable bladders 14 of the configurations described will affordsubstantially complete expulsion of oil from the container, and thenon-resilient and non-permeable bladders 27 will not in any wayinterfere with such complete expulsion of oil, yet will prevent leakageof any gas into the oil chamber.

In the embodiment shown in FIG. 6, the pressure vessel com-prises acylindrical casing 81 having closure caps 82, 83 secured to the endsthereof. Slidably mounted in the casing 81 is a piston 84, whichdesirably has a pair of spaced annular grooves 85 in its periphery inwhich 0 rings 86 are positioned to form a seal with respect to the wallof the casing. As shown in FIG. 6, the piston has an axial bore 87therethrough closed by a plug 88.

Positioned in the casing 81 between piston 84, which acts as apartition, and the end cap 82, is a partition 89, illustratively abladder of thin deformable material whose natural shape is such as tocompletely fill the interior of the container when the piston 84 isagainst the end cap 83.

The bladder 89 illustratively is of substantially nonresilient,non-permeable material such as the types previously described withrespect to the embodiment of FIGS. 1 to 5.

The mouth 91 of the bladder 89 is positioned between the end 92 ofcasing 81, which desirably carries an annular gasket 93, and the end cap82, and the latter has an axial stud 94 extending inwardly therefrom tolimit the: movement of piston 84 toward end cap 82 to prevent sharpfolding of bladder 89.

To avoid extrusion of the bladder through the space between the wall ofcasing 81 and the piston 84, the latter is desirably provided with anannular lip 95 which is secured at one edge to the piston and has itsother edge 96 resiliently engaging the casing wall.

With the construction above described, two fluids such as gas underpressure and oil may be charged through port 97 in end cap 82 and port98 in end cap 83 into the chambers 99 and 101 on each side of the piston84.

between the bladder 89 and piston 84, or if desired, a

slight quantity of oil may be provided in the space S so as to avoid adry contact between the non-permeable bladder 89 and the wall of casing81 which could cause injury to the bladder upon movement of the piston84.

With the constructions above described there is assurance that evenafter the pressure vessels have been standing idle with a pre-charge forlong periods of time, there will be no mixture of the fluids containedtherein.

As many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope of the claim, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

A pressure vessel comprising a rigid substantially cylindrical containerhaving a gas port and a liquid port axially aligned at the respectiveends of the container, a stretchable, resilient, substantially conicalbag in said container in communication with one of said ports and fixedin said container so as to extend axially thereof, said bag having agreater cross section near the fixed end thereof than at its free endand when in substantially non-distended condition, having its side walladjacent the fixed end thereof closely adjacent the wall of saidcontainer and its side wall near the free end thereof spaced from thewall of said container by a distance substantially greater than thatbetween the side wall of the bag adjacent its fixed end and the adjacentwall of said container, the distance between the side wall of the bagand the wall of the container from near the fixed end of the bag to nearits free end being progressively increasing, whereby upon collapse ofsaid bag and subsequent expansion thereof, during the operation of thepressure vessel the free end of said bag will not rub against the wallof said container, and a second partition in said container interveningbetween said ports, said partitions being concurrently movable betweentwo extreme positions in said container, said second partition when inone of its extreme positions being at least of size substantially equalto that of the first partition when the latter has been fully expandedin said container to one of its extreme positions, said second partitionbeing of substantially non-resilient and non-permeable material, andpositioned internally of said stretchable partition between saidstretchable partition and said gas port, said bag and said partitionboth being bladders, each having a mouth, a fitting having a stemextending through said gas port and having an annular flange at itsinner end, a disc encompassing said stem and in juxtaposition to saidflange, the mouth of said second partition being positioned between saiddisc and said flange, a clamp plate encompassing said stem, the mouth ofsaid stretchable partition being positioned between said clam-p plateand said disc, means to urge said flange, said disc and said clamp platetogether securely to retain the mouths of the bladders in position, saiddisc having a passageway therethrough leading into the space betweensaid bladders, and said stem having a passageway extending from theexterior of the pressure vessel and in communication with said discpassageway.

References Cited by the Examiner UNITED STATES PATENTS Re. 23,437 12/1951 Mercier 13830 2,337,771 12/1943 Roberts 138--30 2,380,866 7/ 1945Overbeke 13830 2,532,143 11/1950 Breit 138-30 2,786,488 3/1957 Mercier1383O 2,877,801 3/1959 Mercier 138-30 2,878,835 3/1959 Peterson 13830LAVERNE D. GEIGER, Primary Examiner.

LEWIS J. LENNY, EDWARD V. BENHAM, Examiners.

